Researchers at the Touro University College of Osteopathic Medicine-CA in Vallejo compared outcomes of gabapentin only, osteopathic manipulative medicine (specifically osteopathic manipulative treatment [OMT]), and gabapentin plus OMT interventions in patients with fibromyalgia. Inclusion criteria were as follows: ages 18 to 65 years, diagnosis of fibromyalgia consistent with the American College of Rheumatology (ACR) 1990 criteria, pain present for at least 3 months, and pain in 11 of 18 tender points positive by Dolorimetry. This study was carried out before the 2010 ACR fibromyalgia criteria were published, but the authors note that all patients would have met the 2010 ACR criteria. Exclusion criteria included pain from traumatic injury or structural or regional rheumatic disease, rheumatoid or inflammatory arthritis, or autoimmune disease; significant psychiatric disease or dementia; substance abuse in past 6 months; and breastfeeding or pregnancy.

Twenty-nine of 35 participants completed the trial: 8 received gabapentin only, 11 received OMT only, and 10 received combined OMT and gabapentin. The OMT was administered by “advanced” osteopathic medical students under supervision for 30 minutes, and the OMT techniques used included myofascial release, muscle energy, counterstrain, facilitated positional release, articular ligamentous, high-velocity/low-amplitude, and osteopathic cranial manipulative medicine. These techniques were administered based on structural examination findings at each visit.

Participants who received OMT alone or combined OMT and gabapentin displayed clinical improvements in the pain scale scores (P<.01 and P=.03, respectively), whereas the change for the gabapentin-only group was insignificant. The OMT-only group was the only group to have a significant decline in scores on the Clinical Global Impressions of Health scale (P<.01). Changes in scores on the Fibromyalgia Impact Questionnaire and number of tender points were insignificant. No differences across groups were statistically significant, which was not surprising given the small sample size of this feasibility study. The authors note that gabapentin, an off-label but commonly used intervention, and OMT were safe and clinically efficacious in this population.